1. Graduate Student, School of Civil and Construction Engineering, Oregon State Univ., 101 Kearney Hall, Corvallis, OR 97331.
2. Assistant Professor, School of Civil and Construction Engineering, Oregon State Univ., 101 Kearney Hall, Corvallis, OR 97331 (corresponding author).
3. Assistant Professor, School of Civil and Construction Engineering, Oregon State Univ., Corvallis, OR 97331.
4. Assistant Professor, Dept. of Civil Engineering, MSC01 1070, 1, Univ. of New Mexico, Albuquerque, NM 87131.
5. Associate Professor, Beijing Key Laboratory of Transportation Engineering, Beijing Univ. of Technology, Beijing 100124, China.